2,4-Diaminotoluene · 4-methyl-1,3-phenylenediamine · MTD · Flakes and molten supply
2,4-Toluenediamine is a methylated aromatic diamine with its two amino groups meta to each other on a toluene ring. It sits at the head of the TDI chain — nitrate toluene, hydrogenate the dinitrotoluene, and you have TDA, which phosgenation turns into the toluene diisocyanate behind the world's flexible foam. Away from that chain it is an amine-functional polyol initiator, a dye and pigment intermediate, and a building block for the diethyl-substituted chain extenders used in fast polyurethane systems. It is also a category 1B carcinogen on the REACH Candidate List, supplied only against a confirmed end use. Chelora Amines supplies TDA in flake and molten form, with a batch-wise COA and SDS on every dispatch.
84.08 + 10.08 + 28.01 = 122.17 g/mol
2,4-Toluenediamine — also written 2,4-diaminotoluene, 4-methyl-1,3-phenylenediamine or simply 2,4-TDA — is a toluene ring carrying amino groups at the 2 and 4 positions. It is a colourless to light tan crystalline solid, melting at about 99 °C, that darkens towards red-brown on exposure to air and light. Most industrial volume moves molten.
Its dominant role is as the intermediate between dinitrotoluene and toluene diisocyanate. Toluene is nitrated to dinitrotoluene, the dinitrotoluene is hydrogenated to toluenediamine, and the diamine is phosgenated to TDI — the isocyanate behind flexible slabstock and moulded foam. The second significant use is quite different: TDA is an initiator for amine-functional polyether polyols, where the aromatic ring carries straight through into rigid insulation foam and brings both reactivity and fire performance with it.
TDA carries a serious health classification. It is a category 1B carcinogen, a suspected mutagen and reproductive toxicant, acutely toxic and damaging to the liver on repeated exposure, and it is listed on the REACH Candidate List. It is also prohibited in cosmetic products in a number of jurisdictions. It is supplied here for industrial use under closed handling, with end-use and regulatory checks before an order is accepted.
| Chemical name | 2,4-Toluenediamine |
| Common synonyms | 2,4-TDA, 2,4-diaminotoluene, 4-methyl-1,3-phenylenediamine, m-toluylenediamine, MTD |
| CAS number | 95-80-7 |
| EC / EINECS number | 202-453-1 |
| HS / HSN code | 2921 51 (phenylenediamines and diaminotoluenes; HSN 2921 51 on Indian invoices) |
| Molecular formula | C₇H₁₀N₂ (CH₃C₆H₃(NH₂)₂) |
| Molecular weight | 122.17 g/mol |
| Appearance | Colourless to light tan flakes or crystals; darkens to red-brown in air and light |
| Odour | Faint amine-like odour |
| Melting point | About 97–99 °C |
| Boiling point | About 292 °C at atmospheric pressure |
| Density | About 1.05 g/cm³ |
| Solubility in water | Soluble, markedly more so hot; freely soluble in alcohols, ether and acetone |
| Amine value | About 918 mg KOH/g (two basic nitrogens) |
| Amine hydrogen equivalent weight | About 30.5 (four active hydrogens per molecule) |
| Flash point | About 148 °C (closed cup) |
| UN number | UN 1709, 2,4-Toluylenediamine, solid, Class 6.1, Packing Group III |
| Regulatory status | CLP Carc. 1B; REACH Candidate List (SVHC); prohibited in cosmetics in several jurisdictions |
Figures are typical values for the technical grade. Isomer-mixture grades differ. The values for the material you order are stated on its Certificate of Analysis and Safety Data Sheet.
Two primary aromatic amines, strongly activating, on an unsymmetrical ring. Nearly everything TDA does commercially comes from one of the reactions below.
Both amino groups are converted to isocyanate groups, giving toluene diisocyanate. This is the single largest consumer of TDA worldwide and the reason the 80/20 isomer mixture exists as a commercial grade.
TDA → TDI (–NH₂ → –NCO)The four active hydrogens are propoxylated or ethoxylated to give an aromatic amine-initiated polyether polyol — autocatalytic, high in functionality and built for rigid foam.
TDA + n PO → aromatic polyolBoth amines diazotise and couple, giving bis-azo dyes and pigment intermediates. TDA chemistry sits behind several classical direct and sulphur dye families.
2 × ArNH₂ → bis-diazoniumEach N–H adds across an epoxide ring, so one TDA molecule ties four chains together at an AHEW of about 30.5 — a very low mix ratio and a hard, high-temperature network.
AHEW ≈ 30.5 · 4 active HAlkylating the positions flanking the amines gives hindered diamines — the diethyl and dimethylthio toluenediamines sold as liquid chain extenders for polyurethane and polyurea.
TDA → DETDA, DMTDACondensation with dicarboxylic acids or acid chlorides gives aromatic polyamides and polyamide-imides where thermal stability is the design requirement.
H₂N–Ar–NH₂ + diacid → polyamideReacts directly with isocyanates to give substituted ureas, which is both the basis of its use as a chain extender and the reason moisture and amine control matter in TDI plants.
R–NCO + H₂N–Ar → ureaOxidises readily in air and light, moving from near-colourless to red-brown. Colour has limited effect on reactivity but carries into pale products, so packs are sealed and nitrogen-blanketed.
air + light → darkeningTell us the isomer you need. The isolated 2,4-isomer and the 80/20 2,4 / 2,6 mixture are different products with different prices, different handling and different downstream behaviour. Specify which your process requires at enquiry stage, along with the 2,6 limit if you are buying the pure isomer.
Discuss your processTDA is made by nitrating toluene twice and then hydrogenating the result. The isomer pattern is set at the nitration step and can only be separated afterwards, never corrected.
Toluene is nitrated with mixed acid to mononitrotoluene and then to dinitrotoluene, giving roughly an 80:20 ratio of the 2,4 and 2,6 isomers.
Dinitrotoluene is hydrogenated over a supported catalyst, reducing both nitro groups to amines and giving crude toluenediamine and water.
Water and light ends are stripped under vacuum, and the catalyst is separated and recycled.
Vacuum distillation and crystallisation isolate the 2,4-isomer from the 2,6-isomer and the ortho isomers, taking purity above 99%.
Molten product is flaked or pastillated under nitrogen and bagged in a contained plant, or loaded hot into heated tankers for molten delivery.
TDI plants take the mixture. The 80:20 ratio of 2,4 to 2,6 comes straight out of the nitration step, and the isocyanate made from it is the familiar TDI 80/20 that the flexible foam industry has run on for decades — separating the isomers before phosgenation would add cost for no benefit. Everyone else usually wants the pure 2,4-isomer: polyol producers, because a defined initiator gives a defined polyol structure; dye and pigment makers, because the 2,6-isomer couples to a different shade; and specialty chemical manufacturers, because a mixed feed means a mixed product. If you are buying TDA for anything other than isocyanate manufacture, specify the 2,4 content and the 2,6 limit explicitly.
TDA oxidises more readily than most aromatic diamines. Freshly made flake is close to colourless; left exposed to air and light it moves through yellow and pink to a deep red-brown within days. The change costs very little reactivity — the amine value barely moves — but it carries into the colour of polyols, dyes and finished foam, so colour-sensitive users should specify a limit and order against their own draw-down. Sealed, opaque packs stored cool and dry normally hold specification for twenty-four months. Molten storage should be nitrogen-blanketed throughout and not held hot longer than the process requires, since hot storage accelerates both darkening and vapour exposure.
Isomer content, solidification point and colour are the three parameters that decide which grade suits you. The form decides how your plant handles it.
Isolated 2,4-TDA in flake or pastille form for polyol initiation, dye and pigment intermediates, epoxy cure and specialty synthesis.
The 2,4 / 2,6 mixture as it comes from nitration and hydrogenation, supplied for isocyanate manufacture rather than formulation.
Heated tanker supply for continuous consumers, and high-purity laboratory packs for analytical, research and reference use.
| Parameter | Test method | Typical specification |
|---|---|---|
| Appearance | Visual | Colourless to light tan flakes or pastilles |
| Purity, 2,4-isomer | GC | ≥ 99.0% w/w |
| 2,6-isomer | GC | ≤ 0.5% w/w |
| Ortho isomers, total | GC | ≤ 0.3% w/w |
| Solidification point | Crystallisation | ≥ 97.5 °C |
| Amine value | Potentiometric titration | 910 – 920 mg KOH/g |
| Colour, molten (APHA) | APHA / Hazen | ≤ 150 |
| Moisture | Karl Fischer | ≤ 0.2% w/w |
| Ash | Gravimetric | ≤ 0.05% w/w |
Indicative specification for planning. The controlling document is the Certificate of Analysis issued for your batch. If your process needs a tighter isomer or colour limit, say so at enquiry stage.
One very large outlet, a second substantial one in rigid foam, and a long tail of intermediates and colourants.
The dominant outlet by volume. Phosgenation of the 80/20 isomer mixture gives TDI for flexible slabstock and moulded foam, coatings, adhesives and elastomers.
Alkoxylated to give aromatic amine-initiated polyether polyols — autocatalytic, high-functionality starters for rigid polyurethane and polyisocyanurate insulation.
Diazotised and coupled to give azo, direct and sulphur dyes and pigment intermediates for textiles, leather, paper and inks.
A low-ratio aromatic hardener at an AHEW of about 30.5, giving hard, chemically resistant, high-temperature networks in specialty and electrical systems.
Ring alkylation gives the hindered liquid diamines — DETDA and DMTDA — used as curatives in polyurea spray, RIM and cast elastomer systems.
Condensed with aromatic diacids and dianhydrides for high-temperature resins, films and engineering polymers.
An intermediate for aromatic amine antioxidants, Schiff bases and corrosion inhibitor packages used in lubricants and process chemicals.
A standard aromatic diamine in polymer and dye chemistry research and as an analytical reference material under laboratory containment.
Not for cosmetic use. 2,4-Toluenediamine appears in older hair dye literature, but it is prohibited in cosmetic products in the European Union and restricted or banned in a number of other jurisdictions. We do not supply it for cosmetic applications. If you are sourcing for a personal care formulation, the compliant chemistry is a different substance entirely — tell us what you are trying to achieve and we will point you at it.
Ask about alternativesFrom sofa cushions to insulation board — the value chain downstream of 2,4-toluenediamine.
| Derivative | Made by | End use |
|---|---|---|
| Toluene diisocyanate (TDI) | Phosgenation of the 80/20 isomer mixture | Flexible slabstock and moulded foam, coatings, adhesives, elastomers |
| Aromatic amine-initiated polyols | Propoxylation and ethoxylation of the four active hydrogens | Rigid polyurethane and polyisocyanurate insulation systems |
| DETDA — diethyltoluenediamine | Ring alkylation with ethylene | Fast liquid curative for RIM, polyurea spray and elastomers |
| DMTDA — dimethylthiotoluenediamine | Thioalkylation of the ring | Liquid cast elastomer curative, used as a MOCA alternative |
| Azo, direct and sulphur dyes | Diazotisation of both amino groups and coupling | Textile, leather, paper and ink colourants |
| TDA-cured epoxy networks | Stoichiometric cure of epoxy resin at AHEW ≈ 30.5 | Electrical laminates, chemically resistant linings, specialty composites |
| Aromatic polyamides and polyimides | Condensation with diacids or dianhydrides | High-temperature films, resins and engineering polymers |
Every container carries the Chelora Amines label with product name, grade, net weight, batch number, manufacturing date, UN number and hazard pictograms, including the health hazard pictogram. Packs are sealed under nitrogen and designed to be opened once.
PE-lined, heat-sealed bags of flake or pastille product, or lined fibre drums where a rigid pack suits your charging arrangement. Palletised and shrink-wrapped.
Lined FIBCs with a discharge spout for contained charging into a melt tank or reactor, keeping dust exposure to a minimum.
Heated road and ISO tankers above 105 °C for continuous consumers; 100 g to 1 kg sealed containers for laboratory use under containment.
Pack choice for TDA is an exposure-control decision, not just a logistics one. Tell us how the material will be charged — manual addition, bulk-bag discharge or molten transfer — and we will recommend the pack that keeps your operators furthest from the dust. Export consignments are packed in UN-specification packaging with full dangerous goods documentation and shipped FOB, CIF or CFR through Nhava Sheva and Mundra.
Plan my supplyTDA may cause cancer, is suspected of causing genetic defects and of damaging fertility or the unborn child, is toxic if swallowed and harmful by other routes, and causes damage to the liver through prolonged or repeated exposure. It is absorbed through intact skin. The notes below are a summary for planning only — always work to the Safety Data Sheet, your own site risk assessment and the regulations that apply where you operate.
Regulatory status. 2,4-Toluenediamine is classified as a category 1B carcinogen and is on the REACH Candidate List as a substance of very high concern, which brings notification and communication duties along the supply chain. It is prohibited in cosmetic products in the European Union and restricted elsewhere, and its listing position can change. We ask every buyer to confirm the end use and the regulatory basis for it before an order is accepted, and we recommend you check the current entries that apply in your own jurisdiction rather than relying on a page like this one.
Confirm compliance| Parameter | Specification | Result |
|---|---|---|
| Appearance | Colourless to light tan flakes | Complies |
| Purity, 2,4-isomer (GC) | ≥ 99.0% | Complies |
| 2,6-isomer | ≤ 0.5% | Complies |
| Solidification point | ≥ 97.5 °C | Complies |
| Colour, molten (APHA) | ≤ 150 | Complies |
| Moisture (KF) | ≤ 0.2% | Complies |
TDA is checked before dispatch. Each consignment leaves with the paperwork your QC, EHS, stores and accounts teams need on day one — including the isomer figures that decide whether a batch suits your process at all.
Five steps for a first order of TDA. The end-use and regulatory check in step two is specific to this product.
Isomer grade, quantity, flake or molten, the 2,6 and colour limits you need, how the material will be charged, and your delivery location.
We confirm the intended use and the destination's regulatory position. We do not supply TDA for cosmetic applications.
We quote, then the batch is tested — isomer purity, solidification point, colour and moisture — and the COA and SDS are prepared.
Sealed, labelled packs move under dangerous goods documentation, or a heated tanker is loaded for molten delivery.
Material reaches your gate and repeat dispatches are scheduled to your usage, keeping stored quantities on site to a minimum.
Buyers who order TDA usually source these from the same list. See the full product range for the complete picture.
Short answers to what purchase, lab, EHS and plant teams ask us most. Anything else, ask us directly.
Send the isomer grade, form, quantity, pack size, intended end use and your delivery address or destination port. We come back with a price, the documents that go with the batch and a dispatch or shipping plan, usually within 24 hours.